1. Field of the Invention
The present invention relates to a sheet conveyance apparatus, a sheet cutting apparatus, and an image forming apparatus including a sheet conveyance unit configured to convey a cut sheet.
2. Description of the Related Art
An image forming apparatus, such as a printer, that forms an image on a sheet based on predetermined information is known conventionally. There is known a configuration incorporating a sheet cutting unit or mounting a sheet cutting apparatus in order to obtain a product having a desired size or to remove an unwanted portion, such as a margin between images in continuous image formation, in the case where an image is formed on a long sheet, such as roll paper.
Unwanted sheet pieces that have been cut by a sheet cutting unit or a sheet cutting apparatus (hereinafter, also referred to as a cutter unit) are accumulated temporarily in a trash box and are disposed of after the trash box becomes full. However, depending on the configuration of a cutter unit or on whether or not usability has been taken into consideration, the arrangement of a trash box for accumulating unwanted sheet pieces is limited. Even in the case where a trash box cannot be arranged in a position, which is a destination of unwanted cut sheet pieces that fall freely, it is required for unwanted sheet pieces to be discharged securely into a trash box.
In order to address this problem, Japanese Patent Laid-Open No. 2013-86249 has proposed a cutter unit and a sheet conveyance unit configured to convey unwanted cut sheet pieces as shown in FIG. 8. A long sheet on which an image is formed and which is conveyed in a direction indicated by an arrow A in FIG. 8 (hereinafter, also referred to as a conveyance direction A) is cut by a cutter including elements 801, 802, 803, 805, and 806 in the cutter unit and unwanted sheet pieces (hereinafter, also referred to as cut trash) are cut off. Cut trash T falls freely on a conveyance belt 811. After the cut trash T becomes stationary in a prone position in which the side with a large area of the cut trash T (usually, the surface or backside of the sheet) faces the top surface of the conveyance belt 811, the drive of the conveyance belt 811 is started and the cut trash T is conveyed in a conveyance direction C. After that, the cut trash T is discharged into a trash box 812 by being pinched and conveyed by a pinch and conveyance system including the conveyance belt 811 and a driven belt 813 facing the conveyance belt 811. In this way, even in the case where a trash box cannot be arranged in a position, which is the destination of the cut trash T that falls freely, the cut trash T is discharged into a trash box.